Ratchet wrenches having a mechanism for changing the direction of torque have been well known in the art for many years. Additionally, combination wrenches employing conventional ratcheting capability as well as a rotary movement of the socket shank that is independent of an oscillation of the handle have also been disclosed. The rotary movement, or as also referred to as a free-spinning mode, is used to either pre-tighten a nut or bolt until it becomes finger tight or to remove a nut or bolt after it has been broken loose by the ratchet section of the wrench.
Many of the patents disclosing wrenches with independent rotary motion describe complex mechanical designs requiring that a plurality of rotary drive elements, including the ratchet gear, be operated to produce the required free-spinning mode. Because of this mechanical complexity, the rotary drive may cause the wrench to bind or it may disengage under load from the drive mechanism causing a work stoppage and/or require a wrench repair. Additionally, the wrench wear-out rate is higher and it is more expensive to manufacture and maintain.
A search of the prior art did not disclose any patents that read directly on the claims of the instant invention. However, the following U. S. patents are considered related and indicative of the state-of- the-art:
______________________________________ PATENT INVENTOR ISSUED ______________________________________ 4,318,314 Furedi, E., et al 9 March 1982 4,277,989 Tracy, K. 14 July 1981 4,086,829 Hudgins, J. 2 May 1978 3,733,936 Flynn, W. 22 May 1973 ______________________________________
The Furedi patent discloses a ratchet wrench assembly that is used to unthread or thread a loosened nut or bolt from a threaded shaft. The wrench is comprised of a barrel assembly that includes a clutching mechanism that is connected to the drive shaft. Thus, rotation of the barrel assembly causes the drive shaft to rotate which, in turn, causes the drive stud to subsequently rotate in a responsive rotational direction.
The Tracy patent discloses a reversible ratchet wrench handle in which the actuator for the direction reversing mechanism is located close to the handle that is grasped by the user. This location permits the user to operate the actuator with the thumb of the hand holding the handle. Thus, changing the direction of operation of the wrench is a one handed rather than a two handed operation.
The Hudgins patent discloses a ratchet wrench having a rotational hand-grip speed-handle located around the wrench handle. A drive means is included within the handle that connects the hand-grip to the ratchet means located in the wrench head. The rotation of a nut or bolt is achieved by rotating the speed-handle about its own axis. This feature may be used for final tightening or after the nut or bolt has been broken loose and is being unthreaded for removal. Thus, the wrench may be used in a conventional manner for exerting maximum torque force or used in a screw-driver fashion when only minimum force is required.
The Flynn patent discloses a wrench having both a ratchet drive and a high speed gear drive that is connected to and activated by a rotational hand-grip. To apply a nut to a stud, the nut is initially placed in the socket attached to the shank. The hand-grip is then rotated which transmits the rotational movement of the hand-grip to the nut via a shaft, gears and the socket shank. When the nut is relatively tight, the force of hand hand-grip is released and the wrench handle is oscillated back and forth to effect a normal ratchet operation. To remove a nut, the above steps are reversed, the ratchet being used to loosen the nut until it turns freely and then the hand-grip is rotated to finish removing the nut.